The invention relates to a device for managing the electrical power supply of the multimedia system installed in a motor vehicle, this system being one of the biggest consumers of electricity, particularly on standby when the vehicle is asleep. It therefore contributes strongly to the discharging of the vehicle battery particularly in long-stay parking phases.
A current multimedia system consists either of a single element, a radio set with integrated front panel and display or even a time and outside temperature display device for example, or several optional elements such as the two elements cited previously or a hands-free telephone kit or a navigation aid system or a telematics unit or a DVD player or even a television tuner for example. Each of these elements is linked by a cable to the vehicle's electrical power supply battery and draws a leak current when the vehicle is asleep, a holding current if it keeps certain information like the time or example, and a standby current awaiting wake-up information, by monitoring an ON/OFF button for example.
In practice, each element placed in a unit must remain powered when the vehicle is asleep that is when it is stopped the engine is switched off and the passenger compartment unoccupied, for example to maintain certain functions like time management, saving of certain information in random access memory RAM without backup, monitoring for a wake-up input or an action from the user by pressing a key for example. Obviously the more such reasons there are to maintain the electrical power supply the more the consumption increases.
Similarly, when the vehicle is woken up, only a part of the multimedia system may be invoked, the time and outside temperature display for example, so that the power supply for the other elements is not necessary.